package com.atguigu.boot;

import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

public class Test1 {

    public static void main(String[] args) {
        new E();
        List<Object> objects = Collections.synchronizedList(new LinkedList<>());
    }
}


class A {
    public A() {
        this.m1();
    }

    public void m1() {

    }
}

class B extends A {
    public void m1() {
        System.out.println("B");
    }
}

class C extends B {
    public void m1() {
        System.out.println("C");
        super.m1();
    }
}

class D extends C {

}

class E extends D {

}